One thing interesting to me is that even within a family, even though several have OCD, it manifests itself differently for each. In my family, my father was a perfectionist to the degree that all of us feel he had OCD. My two sisters both have OCD, but each of them in different ways (although we all are perfectionists).

In my own case, my principal symptoms are symmetry, numbers (fascination with patterns, punctuality, not taking more than seven drinks at a water fountain, "lucky" numbers), clothing arrangement (shoes, color of pants and shirts and socks, etc.), and rechecking to make sure I've locked doors, turned off burners, etc.).